Conventionally, teeth are straightened by applying pressure, usually with wire springs, secured to an appliance inserted in the patient's mouth. The wire springs themselves generally make a point or line contact with the tooth, and if proper movement of the tooth is to follow, the point of application of the force can become somewhat critical.
Another conventional method is to band the teeth individually, then by using resilient wires attached to prewelded brackets on the bands, the teeth are moved into proper alignment. A major disadvantage of this is that: 1) the teeth are not permitted free physiological movement and, 2) expansion of the dental arch is difficult to achieve.
While such orthodontic treatment has been generally effective, with springs, elastics and wires, there is not only discomfort in the mouth, but in addition food particles and the like can easily become entrained in the wire mechanisms.